Case IH 518434-19 - ACM – ACM: Multi function handle keypad disconnected

The control module has lost communication with or cannot detect the keypad/buttons on the Multi-Function Handle (MFH).

• MAGNUM AFS Connect
• Magnum AFS Connect Series
• Magnum 250
• Magnum 280
• Magnum 310
• Magnum 340
• Magnum 380
• Magnum 400
• Steiger AFS Connect Series
• Puma Series
• Optum Series
• Maxxum Series

1. 1

   Scan for additional codes using the Electronic Service Tool (EST) to look for related ACM voltage or communication errors (e.g., 518434-09 or 18008).

2. 2

   Remove the armrest cover and inspect all wiring harness connections between the Multi-Function Handle and the ACM for security.

3. 3

   Check connectors and pins for damage, ensure pins are in the correct position, and verify a tight fit. Look for pinched wires within the armrest pivot points.

1. 1

   Power Down

   Turn off the tractor and disconnect battery power to prevent short circuits while working on the ACM.

2. 2

   Disassemble the Armrest

   Remove the retaining screws and bezels on the armrest console to access the internal Armrest Control Module (ACM) and the base of the Multi-Function Handle.

3. 3

   Reseat Connectors

   Locate the specific harness connecting the MFH keypad to the ACM. Disconnect it, inspect for bent pins or corrosion, and firmly reconnect it.

4. 4

   Replace Faulty Components

   If the wiring is intact but the keypad remains disconnected/unresponsive, the internal circuitry of the handle has likely failed. Remove the mounting hardware at the base of the MFH and install a replacement handle assembly.

5. 5

   Reassemble and Clear Codes

   Reassemble the armrest console. Reconnect the battery, connect the EST, clear the fault codes, and test the MFH buttons (e.g., powershift, hydraulics, headland management) for normal operation.